Purpose: to study the criteria of the fellow eye of a unilateral Primary Congenital Glaucoma (PCG) that had been previously operated and compare them to the operated glaucomatous eye and to an age matched healthy control.
Methods: This study was a comparative cross-sectional study that included all unilateral cases of PCG older than 3 years, who attended Mansoura Ophthalmic Center, Dakahlia, Egypt, during 2018–2024. The study included 3 groups. Group A: study cases which are 20 eyes that were presumed to be the healthy fellow eyes of 20 patients diagnosed earlier with unilateral primary congenital glaucoma. Group B: included 24 normal eyes of 18 age matched controls. Group C: included the operated 20 PCG eyes. Complete examination was done including measurement of the horizontal corneal diameter, measurement of intraocular pressure, fundus examination by binocular indirect ophthalmoscope, axial length and CCT were measured by A scan ultrasonography, refraction by hand-held autorefractometer and gonioscopy by Koeppe 14–16 mm lens with a hand-held slit-lamp.
Results: Statistically significant differences in biometric values including corneal diameter, refraction and IOP were detected between the fellow eyes of unilateral PCG and normal age-matched control. The presence of some signs of glaucoma was noted in the presumed to be the normal fellow eye of unilateral PCG cases.
Conclusion: The fellow eye of a previously diagnosed unilateral PCG can have higher axial length, larger corneal diameter, more myopic refraction than normal age-matched controls, abnormal angle on gonioscopy and some corneal signs of PCG.